A rebel Janata Dal-United (JD-U) leader and former minister joined the Bharatiya Janata Party (BJP) on Friday, ahead of the third phase of the Bihar assembly elections.Bhim Singh, a self proclaimed socialist, joined the BJP in the presence of state BJP president Mangal Pandey at the party office here.Singh, who was a member of the Bihar Legislative Council, said: "Nitish Kumar has become arrogant and this forced me to join the BJP."The next round of voting in Bihar is due on October 28.